I was studying a link that Studiot pointed me toward when I suddenly realized that refracted light is turning. It didn’t sink in right away that reflected light was also turning, but then it did.

Is there a difference , should there be a difference between them and acceleration?

 I have a tendency to draw conclusions because I see things that seem similar, I’m beginning to think that maybe I’m wrong in doing so.

Also, is there a difference between a photon following curved space time, and refraction?

overall, I know that they are different things, but the results are similar.

1 hour ago, jajrussel said:

I was studying a link that Studiot pointed me toward when I suddenly realized that refracted light is turning. It didn’t sink in right away that reflected light was also turning, but then it did.

Is there a difference , should there be a difference between them and acceleration?

 I have a tendency to draw conclusions because I see things that seem similar, I’m beginning to think that maybe I’m wrong in doing so.

Also, is there a difference between a photon following curved space time, and refraction?

overall, I know that they are different things, but the results are similar.

OK, the process of reflection of light/photons is simply light being turned back from a reflective surface, so that the angle of incidence equals the angle of reflection. Refraction occurs when light passes from one medium to another of a different density and obviously different speed.

Your other query re light following geodesics in spacetime, pertains  to a vacuum or near vacuum, and thus is different from reflection and/or refraction.

30 minutes ago, beecee said:

OK, the process of reflection of light/photons is simply light being turned back from a reflective surface, so that the angle of incidence equals the angle of reflection. Refraction occurs when light passes from one medium to another of a different density and obviously different speed.

Your other query re light following geodesics in spacetime, pertains  to a vacuum or near vacuum, and thus is different from reflection and/or refraction.

Okay, thank you.

But, in the change of motion are they technically accelerating?

My assumption has always been that a change of motion can not occur without acceleration. Meaning that an applied force is needed for the change to occur. I am also still wondering what the difference is between a geodesic and an applied force is, if the result is a change in motion?

41 minutes ago, beecee said:

Your other query re light following geodesics in spacetime, pertains  to a vacuum or near vacuum, and thus is different from reflection and/or refraction.

Are you saying that light isn’t following a geodesic as it passes through water? In essence isn’t the mass of a volume of water bending space Time?

 I know you didn’t say a thing about water. I chose to use water as an example because it provides the most notable observation of refraction. It also reflects well.

8 hours ago, jajrussel said:

Okay, thank you.

But, in the change of motion are they technically accelerating?

My assumption has always been that a change of motion can not occur without acceleration. Meaning that an applied force is needed for the change to occur.

It certainly changes speed from one medium to another, so technically, your assumption is probably correct.

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I am also still wondering what the difference is between a geodesic and an applied force is, if the result is a change in motion?

A change in frequency, not speed, as light follows the geometry of spacetime.

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Are you saying that light isn’t following a geodesic as it passes through water? In essence isn’t the mass of a volume of water bending space Time?

Of course it follows the geodesic of that spacetime, but also a change in speed as it enters the medium of water, from the near vacuum of space and/or vice-versa.